{"id":"vidhyamitra:day:1980-01-21:en","page_class":"VM-1-day","url":"https://vidhyamitra.com/day/1980-01-21","language":{"target_lang":"en","base_lang":"en","quality_tier":"canonical"},"data":{"date":"1980-01-21","date_display":"January 21, 1980 CE","panchanga":{"method":"Sūrya Siddhānta + Bhāskara-II iterative manda + Kerala-school (Mādhava-Nīlakaṇṭha) evection + variation + annual equation","engine_version":"2.0 (Kerala-school enhanced)","accuracy_note":"Sub-degree on Moon at any Kali-Yuga date (~2-5° residual max)","tradition_chain":"Āryabhaṭa(499) → Brahmagupta(628) → Bhāskara II(1150) → Mādhava(~1400) → Parameśvara(1430) → Nīlakaṇṭha(1501) → this","input":{"year":1980,"month":1,"day":21,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2444259.770833,"kali_year":5081,"ahargana":1855794.2708,"sun":{"sidereal_longitude":276.5529,"rashi":10,"rashi_name":"Makara"},"moon":{"sidereal_longitude":316.8053,"rashi":11,"rashi_name":"Kumbha"},"tithi":{"number":4,"name":"Caturthī","paksha":"Śukla","full_name":"Śukla Caturthī","elongation_degrees":40.2524,"elapsed_within_tithi_degrees":4.2524},"nakshatra":{"number":24,"name":"Śatabhiṣā","pada":4,"moon_longitude":316.8053,"elapsed_within_degrees":10.1386},"yoga":{"number":18,"name":"Varīyān","sum_longitude":233.3582},"karana":{"half_tithi_index":6,"name":"Vaṇija"},"vara":{"number":3,"name":"Somavāra (Monday)"}},"sky":{"method":"Sūrya-Siddhāntic Bhāskara-II 4-step iteration with atan2-based śīghra + varying peripheries + lunar latitude","engine_version":"3.0 (Pūrṇa — complete SS implementation)","tradition_sources":"Āryabhaṭīya 499 CE → SS Ch.1-5 Burgess 1860 → Siddhānta-Śiromaṇi Bhāskara II 1150 → Tantrasaṅgraha Nīlakaṇṭha 1501","input":{"year":1980,"month":1,"day":21,"hour":6,"minute":30,"calendar":"gregorian"},"julian_day":2444259.770833,"ahargana":1855794.2708,"kali_year":5081,"ayanamsa_lahiri":23.5744,"grahas":{"sun":{"sidereal_longitude":276.57326,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":21,"name":"Uttara Āṣāḍhā","pada":3},"retrograde":false},"moon":{"sidereal_longitude":319.53116,"rashi":{"number":11,"name":"Kumbha"},"nakshatra":{"number":24,"name":"Śatabhiṣā","pada":4},"retrograde":false,"latitude":-0.4478},"mars":{"sidereal_longitude":141.90566,"rashi":{"number":5,"name":"Siṃha"},"nakshatra":{"number":11,"name":"Pūrva Phalgunī","pada":3},"retrograde":false},"mercury":{"sidereal_longitude":276.67296,"rashi":{"number":10,"name":"Makara"},"nakshatra":{"number":21,"name":"Uttara Āṣāḍhā","pada":4},"retrograde":false},"jupiter":{"sidereal_longitude":135.41426,"rashi":{"number":5,"name":"Siṃha"},"nakshatra":{"number":11,"name":"Pūrva Phalgunī","pada":1},"retrograde":true},"venus":{"sidereal_longitude":312.66085999999996,"rashi":{"number":11,"name":"Kumbha"},"nakshatra":{"number":24,"name":"Śatabhiṣā","pada":2},"retrograde":false},"saturn":{"sidereal_longitude":153.08975999999996,"rashi":{"number":6,"name":"Kanyā"},"nakshatra":{"number":12,"name":"Uttara Phalgunī","pada":2},"retrograde":true},"rahu":{"sidereal_longitude":131.0888,"rashi":{"number":5,"name":"Siṃha"},"nakshatra":{"number":10,"name":"Maghā","pada":4},"retrograde":false},"ketu":{"sidereal_longitude":311.0888,"rashi":{"number":11,"name":"Kumbha"},"nakshatra":{"number":24,"name":"Śatabhiṣā","pada":2},"retrograde":false}},"panchang":{"method":"Sūrya Siddhānta + Bhāskara-II iterative manda + Kerala-school (Mādhava-Nīlakaṇṭha) evection + variation + annual equation","engine_version":"2.0 (Kerala-school enhanced)","accuracy_note":"Sub-degree on Moon at any Kali-Yuga date (~2-5° residual max)","tradition_chain":"Āryabhaṭa(499) → Brahmagupta(628) → Bhāskara II(1150) → Mādhava(~1400) → Parameśvara(1430) → Nīlakaṇṭha(1501) → this","input":{"year":1980,"month":1,"day":21,"hour":6,"minute":30,"second":0,"calendar":"gregorian"},"julian_day":2444259.770833,"kali_year":5081,"ahargana":1855794.2708,"sun":{"sidereal_longitude":276.5529,"rashi":10,"rashi_name":"Makara"},"moon":{"sidereal_longitude":316.8053,"rashi":11,"rashi_name":"Kumbha"},"tithi":{"number":4,"name":"Caturthī","paksha":"Śukla","full_name":"Śukla Caturthī","elongation_degrees":40.2524,"elapsed_within_tithi_degrees":4.2524},"nakshatra":{"number":24,"name":"Śatabhiṣā","pada":4,"moon_longitude":316.8053,"elapsed_within_degrees":10.1386},"yoga":{"number":18,"name":"Varīyān","sum_longitude":233.3582},"karana":{"half_tithi_index":6,"name":"Vaṇija"},"vara":{"number":3,"name":"Somavāra (Monday)"}},"eclipse_current":{"solar":{"type":"solar","occurs":false,"moon_latitude":-0.448,"elongation":40.252},"lunar":{"type":"lunar","occurs":false,"moon_latitude":-0.448,"opposition_distance":139.748}},"eclipse_window_40days":[]},"calendars":{"vikram_samvat":2037,"vikram_samvatsara":"Śrīmukha","saka_samvat":1902,"saka_samvatsara":"Raudra","bengali_samvat":1387,"malayalam_era":1156,"nanakshahi_year":511,"lunar_month":"Māgha","lunar_month_paksha_full":"Māgha Śukla Pakṣa","solar_month":"Makara (Tai)","ritu":"Śiśira (Winter)","display_summary":"Māgha Śukla Caturthī · Vikram 2037 Śrīmukha · Śaka 1902 Raudra"},"festivals":[{"id":"makara-sankranti","name":"Makara Saṅkrānti (Uttarāyaṇa)","name_sanskrit":"मकर सङ्क्रान्ति","tradition":"Pan-Hindu","associated_deity":"Sūrya Bhagavān","significance":"Sun enters Capricorn; Uttarāyaṇa (north-going) begins. Bhīṣma's chosen mahaprasthāna time.","vrata":true,"detection":{"sun_rashi":"Makara"},"precedence":1,"sources":["Mahābhārata Bhīṣma-Stuti","Sūrya-Siddhānta"]},{"id":"pongal","name":"Pongal / Thai Pongal","name_sanskrit":"पोङ्गल","tradition":"Regional","associated_deity":"Sūrya Bhagavān","significance":"Tamil 4-day harvest festival; coincides with Makara Saṅkrānti.","vrata":false,"detection":{"sun_rashi":"Makara"},"precedence":2},{"id":"vinayaka-chaturthi","name":"Vināyaka Caturthī (monthly)","name_sanskrit":"विनायक चतुर्थी","tradition":"Pan-Hindu","associated_deity":"Gaṇeśa","significance":"Monthly Śukla-pakṣa Caturthī; auspicious for new ventures.","vrata":true,"detection":{"tithi_number":4,"tithi_paksha":"Śukla"},"precedence":6}],"todays_walk":{"walk":{"id":"chandra-walk","name":"Candra Walk","name_sanskrit":"चन्द्र यात्रा","type":"graha","description":"Manas-control + BG 6.5-7.","step_count":5,"url":"/walk/chandra-walk"},"reason":"Somavāra (Monday) — its presiding graha's walk."},"cosmic_resonances":[]},"validity":{"eternal":false,"valid_from":"1980-01-21T00:00:00Z"},"liturgical":{"opening":"जय श्री कृष्ण","closing":"ॐ तत् सत्","attribution":"Computed by Vidhyamitra Sūrya-Siddhānta substrate; Vidhyamitra substrate"},"seo":{"title":"Pañchāṅga January 21, 1980 CE · Vidhyamitra","description":"Vedic pañchāṅga for January 21, 1980 CE: Śukla Caturthī · Śatabhiṣā.","schema_org_type":"Article","canonical":"https://vidhyamitra.com/day/1980-01-21","hreflang_alternates":{"en":"https://vidhyamitra.com/day/1980-01-21","sa":"https://sa.vidhyamitra.com/day/1980-01-21","hi":"https://hi.vidhyamitra.com/day/1980-01-21","x-default":"https://vidhyamitra.com/day/1980-01-21"}},"provenance":[{"pillar":"BOB-History","pillar_version":"2.12.0","method":"Sūrya-Siddhānta first-principles + Bhāskara II + Kerala-school (Mādhava-Nīlakaṇṭha) corrections","retrieved_at":"2026-05-14T08:31:03.260Z","verification":{"type":"multi-marker","confidence":"canonical"}}],"meta":{"generated_at":"2026-05-14T08:31:03.260Z","pillar_versions":{"BOB-History":"Pūrṇa"}}}